Electrical thermostat



Aug. 4, 1936. w p HARPER 2,049,562

ELECTRI CAL THERMOSTAT Filed Jan. 3, 1936 I 3 Sheets-Sheet l i F y: 1 I

1936. w. D. HARPER ELECTRICAL THERMOSTAT Filed Jan. 5, 1936 3 Sheets-Sheet 2 l'nven ar A Home W. D. Harper I llf/lilll.

Aug. 4, 1936. w. D. HARPER 2,049,562

ELECTRICAL THERMOSTAT Filed Jan. 3, 1936 3 Sheets-Sheet 3 Invenlor W. 1). Harper pmm A Home};

Patented Aug. 4, 1936 UNITED STATES PATENT OFFICE 4 Claims.

15 Figurel is a side elevational view of the device.

Figure 2 is a vertical sectional view taken substantially on line 22 of Figure 1.

Figure 3 is a sectional view taken substantially on line 33 of Figure 2. I m Figure 4 is a cross sectional view taken substantially on line '44 of Figure 2.

Figure 5 is a. sectional view taken substantially on line 55 of Figure 2.

Figure 6 is a fragmentary side elevational view '25 of the upper portion of the device partly broken away to disclose the adjustable indicator.

Figure? is a side elevational view of the outside insulating sleeve.

Figure 8 is a side elevational view of the in- 30 side di-electric vial.

Figure 9 is a sectional view taken substantially on line 9-9 of Figure 2.

Figure 10 is a side elevational view of the vial and barrel connector.

36 Referring to the drawings wherein like numerals designate like parts, it can be seen that the device is made up of an outside sleeve generally referred to by numeral 5 which is of glass or some other similar insulatory material, the same 40 consisting of the cylindrical portion 6, open at its top and provided with a reduced depending portion I open at its bottom.

Inside of this sleeve 6 is disposed the vial generally referred to by numeral 8 and this consists 45 of the cylindrical portion 9 for disposition into the cylindrical portion 6 and the depending tube I merging into the mercury containing bulb II. The tube l0 depends through the reduced portion 1 of the cylinder 6 while the bulb I I depends be- 50 low the lower end of the reduced portion 1 as and in the manner substantially shown in Figure 2.

Figure 2 discloses a volume of mercury l2 in the bulb II and as is clearly shown in Figure 2, the cylindrical portions 61 are separated by a 55 filler sheet 13, through which the conductor I4,

is disposed and connected to the electrode l which extends into the bulb II in the manner shown in Figure 2.

Figure 2 also shows that the upper portion of the vial 8 is flanged inwardly as at I6 and provid- 5 ed with an upstanding rib IT. The cylindrical portion 9 defines an overflow chamber for the reception of mercury l2 in the event it overflows through the tube l l Numeral l8 represents a cylindrical metallic shell for the reduced portion 1 of the sleeve 5 as well as for the bulb II, the same being closed at its bottom as at l9, but at this point being provided with slots 20 through which the bulb II is visible. 1 c

The upper portion of this shell l8 flares outwardly as at 2| to merge with the cylinder 22. The cylinder 22 is flanged outwardly as at 23 and extends upwardly as at 24.

Numeral 25 represents an elongated upstanding cylindrical cover closed at its top and provided with a dielectric lining 26. The lower portion of this cover can be slipped over the upstanding portion 24 to serve as a hood for the mechanism which will'be subsequently described. 5'

Numeral 21 represents a threaded core provided with abore extending longitudinally therethrough and a plurality of normally contracted hook member 28 at its lower end as shown in Figure 10.

A barrel 29 is internally threaded to receive the upper portion of the core 21, and as shown in Figure 2, a ferrule 30 is engaged over the lower portion of the core 21. A packing ring 3| is interposed between the ribbed portion ll of the vial cylinder 9 and the lower flanged portion 32 of the ferrule 30. The barrel 29 is provided with an elongated tube 33 which extends downwardly through the bore 21 and between the hook members 28 and when this tube 33 is inserted in the manner shown in Figure 2, the hook members 28 are spread apart in the manner shown in Figure 2. The hook members 28 when spread apart engage under the flanges l6 of the vial cylinder 9 and obviously with the ferrule 30 in the position shown in Figure 2, the core 21 and barrel 29 are supported firmly in position on the upper portion of the vial. Numeral 34 represents a ring of curent conductive material interposed between di-electric rings 35 interposed between the barrel 29 and the ferrule 30 and this ring 34 is provided with laterally disposed lugs 36-41. Conductor wires of a circuit extend through a (ii-electric eyelet 38 in the wall of the cover and one connects to the lug 31 while the other connects to the conductor 4.

Numeral 39 represents an elongated threaded rod, threadedly disposed through the tube 33 and this connects at its lower end to the reduced electrode 40 which depends into the tubular depending portion ll] of the vial 8. A dial disk 4| is secured to the upper end of this rod 39 by a collar and a set screw 42 while a curved head 43 permits adjustment of this rod through the tube 33.

Extending upwardly from the lug 36 is the rod 44 curved at its upper end as at 45 and provided with a nut 46 bearing against a washer 41. Interposed between the lug 36 and the washer 4'! and circumscribing the rod 44 is the elongated spiral or helical member 48 with graduations 49 thereon.

Obviously the nut 46 can be fed downwardly on the rod 45 to compress or release the spiral 48 so as to properly set the same with respect to the dial 4| during a primary test.

Obviously the dial 4| can be set to any position with respect to the convolutions of spiral 48 in which position the operator knows the position of the electrode 40 in the tube ID. A suitable clamp structure 50 can be employed for securing the device to a wall or other structure.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size, and materials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

Having described the claimed as new is:

1. An electrical thermostat comprising a tube of insulation having a mercury bulb at the lower end thereof, a stationary electrode protruding into the bulb, an electrode depending through the tube, adjusting means at the upper end of the last mentioned electrode for controlling the last mentioned electrode, a support, a rod extending upwardly on the support, a helical shaped indicator convoluting the rod and interposed between the said support and the upper end of the rod, and means at the upper end of the rod for adjusting the said helical member.

invention, what is 2. An electrical thermostat comprising a tube of insulation having a mercury bulb at the lower end thereof, a stationary electrode protruding into the bulb, an electrode depending through the tube, adjusting means at the upper end of the last mentioned electrode for controlling the last mentioned electrode, a support, a rod extending upwardly on the support, a helical shaped indicator convoluting the rod and interposed between the said support and the upper end of the rod, and means at the upper end of the rod for adjusting the said helical member, said helical member being of spring material.

3. An electrical thermostat comprising a tube of insulation having a mercury bulb at the lower end thereof, a. stationary electrode protruding into the bulb, an electrode depending through the tube, adjusting means at the upper end of the last mentioned electrode for controlling the last mentioned electrode, a support, a rod extending upwardly on the support, a helical shaped indicator convoluting the rod and interposed between the said support and the upper end of the rod, and means at the upper end of the rod for adjusting the said helical member, said helical member being of spring material, said adjusting means consisting of a washer bearing against the upper end of the helical member, and a nut and threads on the upper end of the rod adapted to be fed against the said washer.

4. An electrical thermostat comprising a tube of insulation having a mercury bulb at the lower end thereof, a stationary electrode protruding into the bulb, an electrode depending through the tube, adjusting means at the upper end of the last mentioned electrode for controlling the last mentioned electrode, a support, a rod extending upwardly on the support, a helical shaped indicator convoluting the rod and interposed between the said support and the upper end of the rod, and means at the upper end of the rod for adjusting the said helical member, a metallic shell for the said tube and bulb, and a cover for encasing the said adjusting means and indicating spiral and adapted for slip connection with the said shell.

WALTER DUSENBURY HARPER. 

